libgcc/libgcov-merge.c

   1 /* Routines required for instrumenting a program.  */
   2 /* Compile this one with gcc.  */
   3 /* Copyright (C) 1989-2017 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgcov.h"
  27
  28 #if defined(inhibit_libc)
  29 /* If libc and its header files are not available, provide dummy functions.  */
  30
  31 #ifdef L_gcov_merge_add
  32 void __gcov_merge_add (gcov_type *counters  __attribute__ ((unused)),
  33                        unsigned n_counters __attribute__ ((unused))) {}
  34 #endif
  35
  36 #ifdef L_gcov_merge_single
  37 void __gcov_merge_single (gcov_type *counters  __attribute__ ((unused)),
  38                           unsigned n_counters __attribute__ ((unused))) {}
  39 #endif
  40
  41 #else
  42
  43 #ifdef L_gcov_merge_add
  44 /* The profile merging function that just adds the counters.  It is given
  45    an array COUNTERS of N_COUNTERS old counters and it reads the same number
  46    of counters from the gcov file.  */
  47 void
  48 __gcov_merge_add (gcov_type *counters, unsigned n_counters)
  49 {
  50   for (; n_counters; counters++, n_counters--)
  51     *counters += gcov_get_counter ();
  52 }
  53 #endif /* L_gcov_merge_add */
  54
  55 #ifdef L_gcov_merge_ior
  56 /* The profile merging function that just adds the counters.  It is given
  57    an array COUNTERS of N_COUNTERS old counters and it reads the same number
  58    of counters from the gcov file.  */
  59 void
  60 __gcov_merge_ior (gcov_type *counters, unsigned n_counters)
  61 {
  62   for (; n_counters; counters++, n_counters--)
  63     *counters |= gcov_get_counter_target ();
  64 }
  65 #endif
  66
  67 #ifdef L_gcov_merge_time_profile
  68 /* Time profiles are merged so that minimum from all valid (greater than zero)
  69    is stored. There could be a fork that creates new counters. To have
  70    the profile stable, we chosen to pick the smallest function visit time.  */
  71 void
  72 __gcov_merge_time_profile (gcov_type *counters, unsigned n_counters)
  73 {
  74   unsigned int i;
  75   gcov_type value;
  76
  77   for (i = 0; i < n_counters; i++)
  78     {
  79       value = gcov_get_counter_target ();
  80
  81       if (value && (!counters[i] || value < counters[i]))
  82         counters[i] = value;
  83     }
  84 }
  85 #endif /* L_gcov_merge_time_profile */
  86
  87 #ifdef L_gcov_merge_single
  88 /* The profile merging function for choosing the most common value.
  89    It is given an array COUNTERS of N_COUNTERS old counters and it
  90    reads the same number of counters from the gcov file.  The counters
  91    are split into 3-tuples where the members of the tuple have
  92    meanings:
  93
  94    -- the stored candidate on the most common value of the measured entity
  95    -- counter
  96    -- total number of evaluations of the value  */
  97 void
  98 __gcov_merge_single (gcov_type *counters, unsigned n_counters)
  99 {
 100   unsigned i, n_measures;
 101   gcov_type value, counter, all;
 102
 103   gcc_assert (!(n_counters % 3));
 104   n_measures = n_counters / 3;
 105   for (i = 0; i < n_measures; i++, counters += 3)
 106     {
 107       value = gcov_get_counter_target ();
 108       counter = gcov_get_counter ();
 109       all = gcov_get_counter ();
 110
 111       if (counters[0] == value)
 112         counters[1] += counter;
 113       else if (counter > counters[1])
 114         {
 115           counters[0] = value;
 116           counters[1] = counter - counters[1];
 117         }
 118       else
 119         counters[1] -= counter;
 120       counters[2] += all;
 121     }
 122 }
 123 #endif /* L_gcov_merge_single */
 124
 125 #ifdef L_gcov_merge_icall_topn
 126 /* The profile merging function used for merging indirect call counts
 127    This function is given array COUNTERS of N_COUNTERS old counters and it
 128    reads the same number of counters from the gcov file.  */
 129
 130 void
 131 __gcov_merge_icall_topn (gcov_type *counters, unsigned n_counters)
 132 {
 133   unsigned i, j, k, m;
 134
 135   gcc_assert (!(n_counters % GCOV_ICALL_TOPN_NCOUNTS));
 136   for (i = 0; i < n_counters; i += GCOV_ICALL_TOPN_NCOUNTS)
 137     {
 138       gcov_type *value_array = &counters[i + 1];
 139       unsigned tmp_size = 2 * (GCOV_ICALL_TOPN_NCOUNTS - 1);
 140       gcov_type *tmp_array
 141           = (gcov_type *) alloca (tmp_size * sizeof (gcov_type));
 142
 143       for (j = 0; j < tmp_size; j++)
 144         tmp_array[j] = 0;
 145
 146       for (j = 0; j < GCOV_ICALL_TOPN_NCOUNTS - 1; j += 2)
 147         {
 148           tmp_array[j] = value_array[j];
 149           tmp_array[j + 1] = value_array [j + 1];
 150         }
 151
 152       /* Skip the number_of_eviction entry.  */
 153       gcov_get_counter ();
 154       for (k = 0; k < GCOV_ICALL_TOPN_NCOUNTS - 1; k += 2)
 155         {
 156           int found = 0;
 157           gcov_type global_id = gcov_get_counter_target ();
 158           gcov_type call_count = gcov_get_counter ();
 159           for (m = 0; m < j; m += 2)
 160             {
 161               if (tmp_array[m] == global_id)
 162                 {
 163                   found = 1;
 164                   tmp_array[m + 1] += call_count;
 165                   break;
 166                 }
 167             }
 168           if (!found)
 169             {
 170               tmp_array[j] = global_id;
 171               tmp_array[j + 1] = call_count;
 172               j += 2;
 173             }
 174         }
 175       /* Now sort the temp array */
 176       gcov_sort_n_vals (tmp_array, j);
 177
 178       /* Now copy back the top half of the temp array */
 179       for (k = 0; k < GCOV_ICALL_TOPN_NCOUNTS - 1; k += 2)
 180         {
 181           value_array[k] = tmp_array[k];
 182           value_array[k + 1] = tmp_array[k + 1];
 183         }
 184     }
 185 }
 186 #endif /* L_gcov_merge_icall_topn */
 187 #endif /* inhibit_libc */